Simplify the expression. $ (n^{7}-4n^{4}) - ( -7n^{5}+5n^{4}-n^{2}) $
Solution: Distribute any negative signs. $(n^{7}-4n^{4}) + (7n^{5}-5n^{4}+n^{2})$ Since we are adding polynomials, we can simply remove the parentheses. $n^{7}-4n^{4} + 7n^{5}-5n^{4}+n^{2}$ Identify like terms. $ { n^7} - {4 n^4} + \color{#DF0030}{7 n^5} - {5 n^4} + \color{#9D38BD}{ n^2} $ Combine like terms. $ { n^7} + \color{#DF0030}{ 7 n^5} + { n^4} + \color{#9D38BD}{ n^2} $ Add the coefficients. $n^{7}+7n^{5}-9n^{4}+n^{2}$